A MUSLIM store worker refused to serve a customer buying a children’s book on Christianity because she said it was “unclean”.

Shopper Sally Friday felt publicly humiliated at a branch of Marks & Spencer when she tried to pay for First Bible Stories as a gift for her young grandson.

When she put the book on the check-out counter, the young assistant refused to touch it, declared it was unclean and summoned another member of staff to serve instead.

Mrs Friday said she was so upset that she has now complained to the store’s management.

Last night politicians and religious leaders supported her in condemning the high street giant and reigniting the debate over religious beliefs in the workplace.

Conservative MP Philip Davies said the refusal to serve Mrs Friday, 69, was “unacceptable” and “damaging” to community relations.

Inayat Bunglawala, assistant secretary-general of the Muslim Council of Britain, described the assistant’s comments as “offensive” and called for Marks & Spencer to carry out a thorough investigation.

Mrs Friday said her trip to the sales in Reading, Berks, with her daughter had been ruined.

“I went to the till and heard the girl say it was unclean and then she got someone else to serve me,” said Mrs Friday.

“At first I wasn’t sure what was going on and then I realised she was wearing a headdress and I clicked that the title of the book had Bible in it. I felt very humiliated and immediately left the store.”

Mrs Friday, from Old Basing, Hants, added: “I have given it careful thought and still feel humiliated that, because I am purchasing a children’s Bible story book, a cashier is able to object and refuse to put it through the till.

“Had this been a copy of the Koran I am confident any Christian person would be happy to do her job, and for this to happen in a Marks & Spencer of all places beggars belief.

“I am not racist but I have vowed never to let a person wearing a headdress serve me again. It will be a long, long time before I shop again at M&S.” Mr Davies, Conservative MP for Shipley, west Yorkshire, said: “I find it unbelievable. We are a Christian country. I’m afraid it is no good for people to work in Marks & Spencer and not serve their products.

“For M&S to put one of their customers in that position is totally unacceptable. If a Christian lady had refused to serve a Muslim on religious grounds there would have been hell to pay.

“In fact, I am sure someone would be sacked if it had been the other way round. But that won’t happen this time, will it? These kind of things do not do anything for community cohesion. In fact, they damage it.”

Mr Bunglawala said: “This appears to be a very regrettable incident and the ‘unclean’ remark was clearly very offensive and unacceptable.

Many Biblical stories complement the teachings of the Koran. We hope that M&S will investigate this incident.” A spokesman for Marks & Spencer said an investigation was underway. “We would like to apologise to Mrs Friday for any offence this incident has caused,” he said.

“Reading is a very multicultural store and we are surprised and disappointed by this reported incident.

“It does not reflect Marks & Spencer policy and simply should not have happened.

“We will remind all staff at the Reading site of our policy and will contact Mrs Friday to apologise for her distress.”

A source close to the shop assistant claimed there had been a misunderstanding.

“I think there was some confusion over what the customer heard,” she said.

But Mrs Friday’s treatment is just the latest example of Muslim staff refusing to serve customers on religious grounds.

In October 2006, Lloyds chemist was forced to apologise to mother Jo-Ann Thomas after a Muslim pharmacist refused her a morning-after contraceptive pill on religious grounds in Rotherham.

A smoker was refused cigarettes at a Cambridge store in January last year because the Muslim shop assistant said it was against her religion to sell tobacco.

Islamic checkout staff at Sainsbury’s who refuse to sell alcohol are allowed to opt out of handling bottles and cans of drink by calling other staff to take their place.

Other staff have refused to work stacking shelves with wine, beer and spirits and have been found alternative roles in the company.

Sainsbury’s said it was keen to accommodate the religious beliefs of all its staff.